Type-Safe Modular Parsing

Code

There are 4 folders under src/main/scala:

• ModOA - Modular version with Object Algebras
• ModClass - Modular version with classes
• NonMod - Non-modular version, modified from https://github.com/ilya-klyuchnikov/tapl-scala
• NonModLM - Non-modular version with longest-match alternative combinator (|||)

Build

This project can be built by Scala's build tool sbt. Just type sbt then compile and run.

To build it manually, add the only dependency from https://github.com/scala/scala-parser-combinators.

Run

1. Type run under SBT:

> run
[warn] Multiple main classes detected.  Run 'show discoveredMainClasses' to see the list

Multiple main classes detected, select one to run:

 [1] ModClass.Test
 [2] ModOA.Test
 [3] NonMod.Test
 [4] NonModLM.Test

2. Select which version to run by the number:

Enter number: 1

[info] Running ModClass.Test
Calculus name:

3. Enter a calculus name (case-insensitive). It will parse every line from file examples/{calculus-name}.tapl, and pretty-print the AST. Those files contain randomly generated expressions, one per line.

List of calculus names

• Arith
• Untyped
• FullUntyped
• TyArith
• SimpleBool
• FullSimple
• Bot
• FullRef
• FullError
• RcdSubBot
• FullSub
• FullEquiRec
• FullIsoRec
• EquiRec
• Recon
• FullRecon
• FullPoly
• FullOmega